How to Append suffix/prefix to strings in a Python list?

In Python, you often need to add prefixes or suffixes to all strings in a list. This is common when formatting data, adding file extensions, or modifying text elements. Python provides several built-in methods like map(), list comprehensions, and reduce() to accomplish this efficiently.

Using map() Function

The map() function applies a given function to each item in a list. Combined with lambda expressions, it's perfect for adding prefixes and suffixes ?

# Original list of strings
items = ['note', 'book', 'pen']
suffix = 's'
prefix = 'my_'

# Adding suffix using map() and lambda
suffix_list = list(map(lambda x: x + suffix, items))

# Adding prefix using map() and lambda  
prefix_list = list(map(lambda x: prefix + x, items))

print("Original list:", items)
print("With suffix:", suffix_list)
print("With prefix:", prefix_list)

Original list: ['note', 'book', 'pen']
With suffix: ['notes', 'books', 'pens']
With prefix: ['my_note', 'my_book', 'my_pen']

Using List Comprehension

List comprehension offers a more Pythonic and readable approach ?

items = ['note', 'book', 'pen']
suffix = 's'
prefix = 'my_'

# Adding suffix using list comprehension
suffix_list = [item + suffix for item in items]

# Adding prefix using list comprehension
prefix_list = [prefix + item for item in items]

print("With suffix:", suffix_list)
print("With prefix:", prefix_list)

With suffix: ['notes', 'books', 'pens']
With prefix: ['my_note', 'my_book', 'my_pen']

Using reduce() Function

The reduce() function from the functools module can also accomplish this task ?

from functools import reduce

items = ['note', 'book', 'pen']
suffix = 's'
prefix = 'my_'

# Adding suffix using reduce()
suffix_list = reduce(lambda acc, item: acc + [item + suffix], items, [])

# Adding prefix using reduce()
prefix_list = reduce(lambda acc, item: acc + [prefix + item], items, [])

print("With suffix:", suffix_list)
print("With prefix:", prefix_list)

With suffix: ['notes', 'books', 'pens']
With prefix: ['my_note', 'my_book', 'my_pen']

Adding Both Prefix and Suffix

You can combine both prefix and suffix operations in a single step ?

items = ['note', 'book', 'pen']
prefix = 'my_'
suffix = '.txt'

# Adding both prefix and suffix
result = [prefix + item + suffix for item in items]

print("With prefix and suffix:", result)

With prefix and suffix: ['my_note.txt', 'my_book.txt', 'my_pen.txt']

Comparison

Conclusion

List comprehension is the most Pythonic way to add prefixes and suffixes to strings in a list. Use map() for functional programming approaches, and avoid reduce() for this task as it's unnecessarily complex.